


A Whole Different Species

by ashandcas (ashriddle4)



Category: Supernatural
Genre: ABO-ish but not really, Animalistic Castiel, Bottom Dean, Breeding Kink, Come Eating, First Time, Knotting, M/M, Mates, Pain with sex, Public Sex, Rough Sex, Smut, Soul Bond, Top Castiel, Trueform, Trueform Sex, Virgin Castiel, Wing Kink, feather fucking, mouth knotting, mpreg but not really, ruts and heats
Language: English
Status: In-Progress
Published: 2015-08-14
Updated: 2016-02-20
Packaged: 2018-04-14 16:53:06
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 6,595
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4572264
Author URL: https://archiveofourown.org/users/ashriddle4/pseuds/ashandcas
Summary: <blockquote class="userstuff">
              <p>Castiel and Dean have been together for awhile, but they haven't had sex yet because Cas has a host of inhuman qualities he thinks Dean will find repulsive. Dean finds them, well, the exact opposite of repulsive.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> WARNING: There's ruts and heats and very, very dirty rough sex that is always consensual and wanted by both parties, but sometimes Cas gets into a very "animal" state of mind and he worries if Dean wants everything they're doing. Cas is very self conscious (im laughing bc that said subconscious for the longest time) about the "inhuman" parts of himself.

In the back of the Impala, Dean threaded his fingers through Cas’s hair, pulling him down on top of him. Cas’s weight over his body could only be described as _holy shit, damn, fuck._ His hard-as-rock dick pressed against Cas’s.

Cas spoke through hot, wet, dirty kisses. “I’m“ kiss “sorry” kiss “we need” kiss “please” kiss “ _Dean,_ stop.”

If there was one order Dean always obeyed, it was that one.

Dean sighed. “Again?” Look, it wasn’t like he was trying to pressure Cas or anything, but they’d been together six months now, and Dean would get stopped every time they’d get to this point. Dean was a pretty sexual dude and yeah, at first, he’d had some issues with the whole two men thing, but eventually, he’d stopped hating that part of himself because that part of himself gave him Cas’s lips and Cas’s fingers and just _Cas_. How could Dean possibly hate that? Dean, however, was ready to introduce a bit more dirty into their relationship.

“I’m sorry, Dean.”

“Cas.”

Cas sat up in the backseat and adjusted his trench coat and tie. “I understand if you um you need to…scratch this particular itch somewhere else.”

Dean groaned and sat up as well, rubbing his hands over his face. “Come on, man. I’m not gonna do that. We can figure this out. I just need you to talk to me, to explain what’s going on. You won’t tell me. You keep saying you’re not ready, which is fine man, but I think there’s more going on here.”

Cas looked at him and frowned. “There is…more.”

Dean touched Cas’s knee and his eyes went wide. “Tell me.”

“You know how I’m an angel?”

“Nope. Never noticed,” Dean said.

Cas glared at him.

“Sorry, buddy. Continue.”

“Angels rarely have sex with humans.”

Dean snorted. “Tell that to your bro, Gabriel.”

“Gabriel is _was_ an exception, though not to some of what I’m about to tell you. To be perfectly honest, I’m not sure how he explained it to his partners.”

“Uh explained what?”

“You understand that this vessel I occupy isn’t really me, don’t you?”

Dean scratched at the back of his neck. “I mean, I guess. I know it – but I don’t think about it much.”

“I think about it constantly.”

“ _Oh._ ”

Cas sighed a bit wistfully and said, “I wish I could take you in my trueform.”

Dean flushed hot, his dick pressing even harder against his fly. He wished for that too all of a sudden. To know Cas as he actually is. “Wouldn’t my eyes like burn out?”

“Yes, Dean, and you’d likely vaporize.”

Dean frowned, but he made joke because he was Dean. “Kinky.”

Cas rolled his eyes. When Cas made gestures like that, Dean could hardly believe that Cas wasn’t at home in that vessel.

“So what you’re saying,” Dean continued, “is that you won’t fuck me because it won’t feel like it’s you doing it?”

“Not entirely. Yes, I would prefer to mate you as I am, but I know that will never be possible.”

“Yeah that would be – wait _mate_?”

Cas blushed and his eyes got really wide. Kind of looked like he did at that brothel. “I did not mean to say that aloud.”

“Well cat’s out of the bag, pal. So fess up.”

“There are, Dean, several issues with us engaging in sexual intercourse. A) I can’t make love to you in my trueform, as we’ve discussed,”

“Unless I’m up for vaporization.” He ignored the ‘make love’ statement.

Cas gave him a look.

“Don’t look at me like that. You’re the one who’s rejecting me via outline, which is a new one for me.” God, Dean hoped Cas wasn’t really rejecting him. Dean could live without sex if he had the other stuff. Maybe he should make that clear, but Cas continued before Dean could voice that.

“B) Given our relationship and our bond, if we have sex I will mate you.” _What the hell does that mean?_ “C) If I mate, I will begin rather animalistic rut cycles” _Let’s rephrase, what in the HOLY hell does that mean?_ “D) I will knot you and I will want, desperately, to breed you.”

Dean’s mouth just fell open. “What the fuck you talking about?”

Kicked-puppy Cas stares down at his sock-covered feet. His shoes were outside by Baby’s tires with Dean’s boots on this isolated dirt road. “I’m not _human,_ Dean, and the more we’re together and in more ways, you’ll begin to see that. You’ll begin to resent me for it.”

Dean doesn’t know what do with Cas’s confessions but he needs more information. “What does ‘mate’ mean?”

“I would claim you with a bite then my grace and your soul would fuse. This happens rarely, but the cases I know of…it’s plausible you’ll take on a few angelic traits.”

“Dude, will I sprout wings? ‘Cause that would be bad ass.”

“It’s highly unlikely.”

Dean had another question and he hurried to remember what it was. “Uh, what’s a rut cycle?”

“It’s something that only happens to mated angels. About four times a year, I will lose a great deal of control over my vessel and its urges, including an almost insatiable need to mount and knot my mate many times over the course of several days. You’d be very red and swollen by the end because I’d be in too frenzied a state to heal you.”

Dean felt all the blood rush out of his head. This was just too much. “You keep saying knot? What the fuck is a knot?”

“You know how canines, as well as some other species, tie off when-“

“Whoa, you mean like a knot, knot, like a dog.”

Cas kind of hunched over on himself. “I’m not a dog.”

“I know that.” Dean had a thought. “So if your knot thing is the big problem.”

“It’s one of many problems Dean as I have-“

“Yeah, whatever, hear me out. Couldn’t I just like _top_.”

Cas let out a little snort-laugh.

“Hey,” Dean said and punched Cas’s arm. “I’ll have you know I’m a hell of a top with the ladies.”

“While I don’t doubt your sexual prowess with females, every time I’ve been beneath you while we kissed you’ve flipped us so I was on top. Without exception.”

That was ridiculous because he was totally on top when they were making out that time in Topeka – or wait, no…was it that motel outside of St. Louis – no, not then – dammit.

Dean blushed. “What, that’s – you did that.”

“I really didn’t Dean, though I’d be remiss if I omitted that every time we touch and kiss, my grace screams for me to mount and knot you.”

Dean buried his face in his hand and muttered “Oh my fucking god.” There was one final question Dean had though, “You said, you said, holy shit, you said you’d want to breed me.”

“I will want that.” Cas shrank a bit like he just wanted to flap out of here, but he didn’t. “I do.”

Dean was lost for words until he choked out, “Could you?”

“It’s unclear.”

Dean leaned his back. “Fantastic. You know I don’t have the parts for that right?”

“It would be nothing like a human pregnancy.”

“So no pickles and ice cream cravings?”

“Mostly you’d crave my dick. So no change for you really.” Cas jolted back like he wasn’t even sure where that came from, and Dean could not believe Cas was capable of a dirty joke. It was all so bizarre that Dean just started cracking up and Cas just looked over at him with a cocky little grin, but eventually it all faded.

“I’m not quite sure what to do with all this,” Dean said.

Cas frowned. “Me neither.”

“I’m fine, ya know, man. With not ‘doing it’. Taking care of it myself or whatever. We can just keep doing what we’ve been doing.”

Hope in his eyes, Cas looked at him. “Really, Dean?”

Dean nodded. “Yeah, buddy, really.”


	2. Chapter 2

**Notes for the Chapter:**

> Hey folks! Thanks for all the subscribes and kudos and comments. I love it!

For about a month, Dean and Cas continued on as they had been. Unfortunately, Dean could not shake the images his discussion with Cas had implanted in his mind.

_Dean with his ass in the air._

_Cas biting into Dean’s neck, growling._

_Dean egging Cas on as he plowed into him._

Dean had started to wonder why any of that would be a bad thing, though the breeding thing freaked him out. The knot too. Okay, a lot of it freaked him out. Not necessarily in the worst way just in a ‘whoa this unexpected and new’ sort of way.

This evening, Sam had gone to a movie with some girl, leaving he and Cas alone in the bunker. They sat across from each other at the kitchen table. Cas was scrolling through his phone as Dean was licking day-old apple pie off the crooked tines of an old fork.

With his mouth full, Dean surprised himself by blurting, “How big is it?”

Cas looked up from his phone and narrowed his eyes in focus. “How big is what?”

“Your um your you know?” Dean asked.

“My cock?” Cas said.

“Jesus, no.” Though it wasn’t that far from what he was asking. “The other thing?”

Cas tilted his head. “My knot?”

Dean gulped and nodded.

Cas’s lips curved into a frown as his gaze tucked away from Dean. “It’s quite large, Dean. It would…hurt you.”

Dean did everything he could to shove back the image of his own ass stretching around a huge knot, locking him to Cas. _Don’t ask this, Dean. You shut up, don’t ask._

“Think I could see it.”

They hadn’t done anything sexual with each other. Whenever it got to that point, Dean would head to the bathroom to finish himself off and rush back to Cas as quickly as possible to enjoy those post-orgasm moments together. (Well, post _Dean’s_ orgasm, which was starting to seem really unfair).

“Why would you want to? It’s…I can’t.”

Dean sighed. “It’s not like you can hurt me if I’m just watching. You can’t mate me from like six feet away, can you?”

“It’s not that, Dean. If you see that, then you’ll _see_ it. You’ll see what I am.” He stared down at his hands. “An animal, a beast.”

Cas defining himself as a beast made Dean hot all over, and if that wasn’t fucked up, he didn’t know what was.

“You’re an angel, Cas. I know what you are.”

“You’ve never understood what angels are.”

Dean whispered in Cas’s ear as gruff and dirty as he could manage, “Then show me.”

 

. . .

 

Cas lay naked on Dean’s bed. Dean had never seen him naked before, but Cas was all corded muscle and pale skin with dark nipples; his fucking enormous cock was nestled in dark brown, nearly black, hair. He arched back on the bed, thrusting into his own slick grip. Dean leaned against his dresser, rubbing it out on the heel of his hand and devouring the scene before him.

A growl rumbled from Cas that went straight to Dean’s erection. Dean whined in response. _Where the fuck did that come from?_

“Knot you, Dean,” Cas panted as he bucked into his hand. “You should be on my cock. Always. Filled up with me.”

“Yeah. Yeah, please” Dean pulled out his own dick and started tugging it hard. He’d worry about chafing later, all he needed now was to relieve that built up tension. “I’d take it. Do it, Cas. Fuck me. _Mate_ me. Make me yours.”

He’d meant it mostly as dirty talk because Dean had a sinner’s mouth on him, but Cas was across the room in an instant, ramming him back against the dresser. Dean’s hands gripped into Cas’s bare shoulders.

“Cas?” Dean asked, but Cas just snarled and shoved Dean across the room. Cas manhandled and bent Dean over the bed before Dean could really register what was happening. Cas tore Dean pants off, actually _tore_ them, tossed them aside like useless scraps of denim.

Dean pushed back on Cas half-heartedly, like he was trying to shake him off, but Dean would have been upset if he succeeded. Thankfully, the action didn’t deter or slow Cas in the slightest. Dean was pretty damn sure Cas was gonna fuck him, and this wasn’t exactly how he’d imagined their first time. They’d at least had dinner first, some foreplay, one of those motels that had magic finger beds. Because this wasn’t just Dean’s first time with a man, but also Cas’s first time _ever._

Still, Dean wasn’t protesting because he’d resigned himself to never having this anyway, and he wasn’t sure he’d ever in his life been as turned on or wanted something as much. Yeah, he was more than up for this.

Cas leaned over him and bit down on Dean’s neck. He shouted “Fuck” as it broke skin. He could feel hot blood pouring out of the wound, but arousal shocked through his body at the bite. Dean came untouched all over his bed in helpless, little shots.

Since Dean came, for half a second, he thought it was over, but then Cas nailed into him without warning. Cas was still lubed up from touching himself, but Cas’s cock was LARGE and Dean hadn’t been prepped. It hurt like shit until the pain all flooded out of him in that sort of sudden way it did with Cas’s mojo.

When Dean moved, Cas just growled again and pinned him harder to the mattress with his teeth. Dean had very little time to process the information _I’m taking it up the ass_ before Cas just grabbed his hips and started rutting wildly into him.

Dean was spent and soft, but Cas fucking him over and over again felt fantastic. His own dick was flopping, but having the other man inside him, being so full, so pliant - Dean hadn’t known how much he wanted this until he had it. Cas let go off the mark on Dean’s neck and started growling, “ _Mate, mine, good, mine. Knot.”_

Something huge and new started to pull at Dean’s rim, stretching him out so far he was pretty sure he would tear, but Cas could fix that right? Anyway, he was probably just being overdramatic. Still, the knot stung as it finally locked into place and tied him to Cas. This knot that was at least as big as two cocks. _At least._ Tears wrenched themselves from Dean’s eyes and soaked the sheets.

Cas roared as he came which scared ever-loving fuck out of Dean because it didn’t sound like a noise a human would make. It sounded exactly like a lion.

In that instant, Dean imagined being mounted, claimed, by goddamn winged lion. But when a human hand brush against his cheek, it reminded him this was just Cas, his Cas. Well, until he saw a flash of black feathers.

Dean screwed his neck up to look over his shoulder. Sprouting from Cas’s back were two enormous black wings.

“Dude, your wings.”

Cas made a contented purring sound and hauled Dean onto the floor.

“Couldn’t you have pulled us _onto_ the bed instead of _off_ it.”

Still, Cas stayed silent and clearly Cas wanted Dean quiet too because he shoved some immovable fingers into Dean’s mouth like a gag, but Dean could still breathe easily around them. Cas folded his wings around them both, locking their bodies even closer together.

“Fuck,” Dean said as Cas came in his ass again and the knot grew larger. It stung like hell for a second, then the pain disappeared.

“You breed so well,” Cas muttered against Dean’s ears. “Sleep for me, mate.” And, just like that, Dean was out.


	3. Chapter 3

**Notes for the Chapter:**

> So excited to see all the kudos and subscribes! Special thanks to my commenters. Please drop by and tell me what you think. I love talking to everyone!!
> 
> This is a shorter chapter. Sorry about that :)

When Dean woke up his ass was empty and clean. Not sore at all. He had also been dressed in boxers and t-shirt and was now lying under the covers in his bed. His heart dropped. Was Cas gone? But Cas was sitting on the edge of the bed looking at back him. Sleek black wings held tightly to his back.

“Hey.” Dean yawned.

“Hello, Dean.” Cas frowned. “I wasn’t sure if you’d want me here when you awoke, but I figured you had every right to confront me.”

Dean sat up in bed, stretching his tense muscles. “Confront you about what buddy?”

Cas stared down. “I would ask for your forgiveness, but I know I do not deserve it.”

“What are you talking about?”

Cas scrunched his face together, jaw tightening. He swallowed. “I – I took you without consent, Dean.”

Dean blinked a bunch of times and shook his head. “What? No. No, you didn’t. I’m pretty sure I remember something along the lines ‘Yeah baby mate me, knot me’.”

“Yes, Dean, but you didn’t mean-“

“I did. I really did. I wanted it.”

A smile fluttered across Cas’s lips, but then disappeared. “I hate being like that.”

“Like what? Fucking sexy?”

“Not having control. The knotting, the mounting – all of it. We should be able to make love.”

Dean rubbed his face. “I’m not really the making love type, Cas.”

Cas sighed. “Maybe, Dean, but I…I am. I wonder will I never get that? Slow and deep and easy with you?”

Dean scooted over to Cas. “I’ll bet if we do it wild and crazy enough times, we’ll get all those hormones or whatever out and we can be all romantic and gross if that’s what you want.”

“You think so?”

Dean gave a cocky grin. “I wouldn’t be opposed to trying.” Dean reached out and stroked Cas’s wing. The feathers were softer than they looked. Cas jumped all the way across the room.

“How did you do that?”

“Do what?”

“Touch my wings.”

Dean shrugged. “I don’t know. I saw them so I touched them. Sorry for not asking. I should have.”

“It’s not that, Dean. You can see them? Since when?”

“Since the whole sex thing, Cas. I thought you just like poofed ‘em into sight or something.”

Cas looked offended at the concept. “I most certainly did not _poof_ them. My wings are always visible, at least to angels and demons as well. Not to humans, except the shadow when I want it to be. This must either be because we are mates or because of the angelic traits you may get from that bond. I’m not quite sure. Time will tell.”

“Does it matter? Because either way I find them really sexy.”

“You do?” Cas fidgeted with some of the feathers on his right wing. “I thought you’d find them intimidating at best, ugly at worst.”

Dean slid off the bed and made his way back over to Cas. Dean gripped his fingers into Cas’s wings, and Cas responded with a full-bodied shudder.

“ _Dean,”_ Cas purred.

“I do find them a bit intimidating, but that’s part of the appeal.”

“You’re a strange man, Dean Winchester.”

Dean grinned. “Hey, you’re the one that mated me. Maybe that says more about you than me.”

Dean leaned forward and tugged on one of the feather with his teeth. Cas hissed.

“That hurt?” Dean asked, nuzzling into Cas’s wing.

“Good hurt,” Cas mumbled. “Didn’t know there could be good hurt.”

“Oh you bet there can.” Dean tugged on the feather again. Cas yelped, but then groaned, pushing his wing toward Dean’s mouth. Dean smiled.

“Was what I did last night? Was that good hurt?”

Dean grumbled low and deep and suckled on one of the soft feathers as he nodded. It tasted almost sweet.

“If you don’t stop, I’ll mount you again.”

“That’s terrible incentive to stop.”

Cas gripped Dean’s hair and pulled his mouth away. Dean whined. He liked being near Cas’s wings.

“Come on.” Dean wasn’t above pouting at this point so that was exactly what he did. He wouldn’t be above begging either.

“I can’t right now, Dean. I can feel heaven summoning me. I have to go.”

Dean stood up and kissed Cas on the mouth. “All right, get out of here.”

“I won’t be long,” Cas said.

Dean did his best not to react to Cas leaving, but he felt a more distinct pang of loss at the separation. Must be the mating thing… _wonderful._ Though, if Dean thought about it, it was pretty wonderful.

But, shit, how was he gonna explain this to Sam?


	4. Chapter 4

**Notes for the Chapter:**

> Thanks for all the kudos and the comments. Please let me know what you think! I love hearing from you.
> 
> Sorry no smut in this chapter again, but plenty in the next chapter.

Dean waited 45 minutes after Cas left to go talk to his brother. He needed time to prepare what he was going to say. At least, Dean had already had the more difficult conversation of telling Sam that he and Cas were together at all. Finally admitting his attraction to men had been a huge, huge step. He really hope Sam wouldn’t freak out though Dean thought he’d freak out if the roles were reversed.

Dean found Sam standing in the kitchen with the ingredients for a roast beef sandwich spread across the counter.

“Uh, hey, Sam, can I talk to you?”

“Sure, Dean. What is it?” Sam kept his focus on the sandwich as he smeared mayo across a slice of bread. Sam closed up his sandwich and spun around to face Dean. He took a large bite.

“Cas and I are mates.” Okay, that was not how he meant to phrase it.

Sam spoke with his mouth full. “Wha-?”

“Um- well, uh.”

Sam swallowed. “Great explanation, Dean. What do you mean mates?”

“Cas is an angel.”

“I’m really not following this explanation.”

“That’s because you’re not giving me time to talk Sam!”

“Sorry,” Sam took another bite, “Please continue.”

“Cas is an angel which means he isn’t really human which means he does things that humans don’t really do.”

“What? Like smiting demons?”

“There are other things.”

There was a long paused followed by Sam saying, “…are there _sex_ things?”

Another long pause.

“Ew, Dean. I don’t want to know about that.”

“Shut up, Sammy. I’m not gonna explain how we do it.”

“Good – wait you guys actually did it?”

After a bit too much whiskey Dean _may_ have admitted to Sam his whole abstinence problem.

“Yep…and now we’re mates.”

“A plus on the sex, Dean, but I still have no clue what you’re talking about.”

Dean sighed and pulled back the collar of his shirt, revealing the bruised, red bite Cas had left him. Sam’s eyes went wide.

“Jesus, Dean. Cas needs to chill on the hickeys.”

“It’s not a hickey, dick , it ‘s a mating bite.”

“Hold up, hold up. You’re telling me that angels mate? Like they mark and mate and whatever the hell else?”

“Yup.”

Sam focused on Dean so intently Dean swore he could see the gears grinding. “So basically you’re telling me you and Cas all but tied the knot?”

Dean snorted. “Like you wouldn’t believe.”

Sam raised an eyebrow. “Huh?”

“Nothing. Just I do need to warn you that Cas said I may exhibit some angel-like characteristics as a result of the mating.”

Sam smirked. “You gonna grow wings?”

“Right, man. I wish, but Cas says no. Anyway, this was just a heads up. We’ll figure it out as we go.”

“Where is he?” Sam asked. “Did he fuck and run?”

Dean rolled his eyes. “No. He’s in Heaven I think. He said they were summoning him. Oh one more thing.”

Sam had a bite in his mouth but looked at Dean to show he was listening.

“It’s possible Cas could knock me up.”

Sam spit his mouthful of sandwich all over the floor.

“Ew, dude. Gross,” Dean said. Dean pretended to be unconcerned but the concept did nag at the back of his mind and Cas hadn’t been very detailed on the process.

 

. . .

 

Cas stood in a room of blinding white light. He was wearing his vessel as he nearly always did to keep it safe, but he was greeted by another seraph, Hannah, who was not.

It was hard to describe the look of seraph’s true form in human words. The best Cas could do would be to say her hands were fire, her face was lightning and her voice was the sound stars make when they implode.

“Hello Hannah,” he said.

“Do you know why you’re here Castiel?” Hannah said in Enochian, in her true voice. Cas only understood this reply because he was an angel himself.

“Not exactly. No.”

“You mated the Winchester.”

“I did,” Cas said simply.

“You shouldn’t have done that.”

A primeval anger surged inside him, a desire to defend his mating bond. “Heaven knew we were together.”

“Yes, it did, Castiel, but we did not expect you to utterly ignore the consequences of such a bond.”

“You expected me to never make love to Dean?”

“A mating between a human and an angel is incredibly rare, and there are complications.”

Cas shook his head. He didn’t want to listen to this. He wanted to get back to Dean and fill him up again. “I’ve explained to Dean-“

“Did you, Cas? Did you explain what happens if you succeed in breeding him as I can tell your grace craves? Did you explain to him what happens to nephilim?”

Cas lunges forward at Hannah. In her true form, she stops him easily.

“I’m not saying this to upset you, brother. I’m saying it because I would think the last thing you and Dean want is another war with heaven.”

Cas shook his head. “That can’t be what we’re talking about.”

“That is exactly what we are talking about. If you refused to turn over the nephilim to be destroyed, Heaven would have no choice but to hunt the abomination down ourselves.”

“Hannah.”

“I have to go now, Cas. Please think about what I’ve said. If not for your own sake, for Dean’s.”

 

. . .

 

“We can’t be together like that anymore.” Cas stared down at his feet, his wings tucked back sadly. He hated seeing Cas like this. “I’m so sorry, Dean.”

Dean didn’t like the news either. His body had been begging him to bend over for Cas since the moment Cas got back to the bunker. Ignoring that urge would be hard – but he couldn’t just give it up all together. He wouldn’t.

“You have to knot my ass to breed me, right?” Dean asked. His mouth had already gone dry with arousal.

Cas looked at Dean and nodded. “Yes.”

Dean dropped to his knees in front Cas and looked up at him. “Then don’t knot my ass buddy. Knot my mouth.”


	5. Chapter 5

**Notes for the Chapter:**

> I don't know what happened - don't even ask :P but seriously this is just all weird af smut, enjoy!

“Dean, I don’t think this is a good idea.” Cas’s lips were open and a red flush stained his cheeks. His wings were flipped out a bit behind him. He looked regal, like an angel king.

“Why not?” Dean pressed his face to the bulge in Cas’s pants. He was getting so damn hard and Dean loved it. Making Cas hard for him.

Cas’s hand gripped Dean’s hair and pulled him back. “Have you ever even had a dick between your lips before?”

Dean’s stomach dropped, all the pressure in his body moving between his legs. The way Cas phrased things would be the death of him.

“Well no but-“

“But what Dean?” Cas slipped two fingers into Dean’s mouth, pressed down on his tongue, his bottom jaw, opening it. “You wouldn’t be able to breathe.” His fingers slipped back out. Dean immediately missed the pressure. “I would choke you.”

“Don’t wanna breathe. Want you, man.” Dean tugged down a little on the collar of his t-shirt, exposing the bite to Cas. “Don’t you want me?”

Cas’s wings flared out behind him, his hands clenched into fists. God, he was hot like that, all power and control, enough to swallow Dean up.

“Take your clothes off,” Cas growled. “All of them. Now – and don’t make me wait.”

Dean rushed to yank of his t-shirt and tug down his jeans and boxers. Thankfully, he wasn’t wearing shoes or socks. Meanwhile, Cas grabbed a pillow and dropped it on the floor. Cas pointed to the pillow.

“Get on your knees.”

Cas had his pants unbuttoned and opened. His cock was already full, long and thick as it could be before the knot. Dean gulped.

It was strange – this sort of reaction Dean had to the scene of Cas looming over him, wings unfurled and dominating. Dean’s hands slipped behind his back, his eyes cast down and his face turned away and down, the mating bite aiming up at Cas’s gaze.

Dean could barely see it, but Cas ran his hand over his own dick a few times, then swept his thumb over the tip. There was a little glistening drop on his thumb that he pressed against the mating bite and rubbed it in.

That animalistic growl rumbled from Cas’s lips. Wings bracketed behind Dean’s back, supporting him with their soft feathers, pushing his head back up to look at Cas. Suddenly, the tip of Cas’s cock prodded at Dean’s lips and Dean immediately opened to him. Cas shoved his dick in all the way until Dean’s lips were wrapped around the base. Dean could not breathe – at all – he struggled back against the wings, a little worried, but the wings held him in place.

“Dean. Give into me,” Cas whispered.

Locking his gaze on Cas’s, Dean steadied himself, remained calm even without the benefit of oxygen. Moments later, Dean realized that though he wasn’t breathing, he still felt fine. There were some perks to getting fucked in the mouth by an angel.

Cas took his time. Long, slow slides in and out of Dean’s mouth. He’d press all the way in and then touch Dean’s neck, asking him to swallow around him so Dean did. Cas’s wings slid down Dean’s back, petting him softly, nudging down between his ass cheeks. Dean’s mouth and lips burned and ached, the focus of Cas’s grace on keeping Dean from suffocating. He hardly felt conscious anymore, but it was so good to be held like this, to be used for Cas like this.

There was something so soothing about the feeling of Cas slowly moving against his tongue, about the way he stood so still and strong as he fucked Dean’s mouth. It was only when Dean caught sight of the clock on his dresser that he realized Cas had been doing this for nearly an hour.

Cas slammed in deep one more time and something even wider pulled at Dean’s mouth, Cas’s big knot, and then Cas came so much and so hot Dean could feel it pouring down his throat. Those tears started forming in his eyes again and Dean would really like to get fucked without crying for once, but what could he do? It was beyond anything he imagined to have a heavy knot on his tongue and huge dick down his throat. (Lucky Cas kept him from gagging too). When the knot was locked in place, Cas groaned as he touched himself through the skin of Dean’s neck.

“Look,” Cas said low and dark. Cas pulled his wings back, giving Dean access to the full-length mirror.

Dean’s lips were so red they were almost purple, wet and swollen around Cas’s knot. Dean’s face was streaked with tears, and he could actually see the shape of Cas’s dick bulging in his throat.

Something inside Dean, maybe whatever the mating bond was changing, drew Dean to lean his forehead against Cas’s pelvis. Huge, strong wings scooped him up and supported him to the bed. The wings spun him around, the knot rubbing against his lips as it turned, so Dean’s ass was up by Cas’s face.

When Cas’s tongue came down on Dean’s rim, Dean squirmed but Cas’s wings held him down again. They weren’t really sexual licks – just long and soft, almost like Cas was grooming Dean, getting him wet. Then Dean felt something soft press against hole and then slip inside – then he felt another just like it.

Was Cas shoving _feathers_ into his ass? What the fucking hell? Again, Dean squirmed, a little uncertain. This time, Cas snarled and slapped between Dean’s cheeks hard enough to sting. The touch reminded Dean that he trusted Cas and there was something annoyingly hot about having angel feathers inside him. He just hoped it wouldn’t be hard to get them out…

Cas continued putting more feathers inside Dean, but as he did, he started tugging on Dean’s dick, twisting and pulling, fingers sliding against him in all the ways he loved and needed until Dean pleasure was curling all around him and he came in Cas’s hand. Dean felt so stuffed, mouth and ass filled with Cas. And so…sated. So comfortable. He could stay like this forever and who would fault him?

When the knot went down and Cas pulled out, Dean whined. He didn’t even know he could make that noise. Cas tugged Dean around to face him. Cas held out his hand and opened it. He still had all of Dean’s come on his palm. Cas thrust it closer to Dean’s mouth

“Uh, what?”

Cas just held his hand right up to Dean’s lips. “Please,” Cas whispered in this voice that somehow Dean knew wasn’t English even though he could understand the meaning.

Dean leaned forward and licked the come off Cas’s hand with three long slides of his tongue. It tasted sweeter than most come, but Dean didn’t think much about it.

“Your lips are so swollen,” Cas said, his voice back to normal.

“Don’t heal ‘em,” Dean replied. “Like it this way.”

“Oh Dean.”

“And man not that it wasn’t crazy unexpected and crazy hot, but like how am I supposed to get all these feathers out?”

“You won’t. You’ll keep them in for me.”

“But Cas?”

“It’s fine, Dean. It won’t be long before they dissolve.”

“What are the feathers for?”

Cas shrugged. “It’s another way for me to claim you, to fill you up with me. Also, they’ll feel good as they dissolve. You’ll see.”

Dean pulled away from Cas and laid his arms out in front of him, lifting his ass in the air. The mirror caught another look at them and Dean saw the tips of a few black feathers coming out of him.

“Want you to put more in,” Dean said.

“You already look rather stuffed to me. I’m not sure I should, Dean.”

“Just one more,” Dean asked and he felt like he’d be saying just one more for a long time.

. . .

Cas wasn’t sure how to tell Dean. He clearly had been too distracted to notice how easily the feathers went into him or maybe he just assumed it was another benefit of Cas’s grace, but it was something else. Something Dean would probably hate – _and then he’d hate me_ , Cas thought.

Dean was wet, leaking sweet-warm slick. This was a change Cas had never expected and made Hannah’s threat even more concerning.


	6. Chapter 6

**Notes for the Chapter:**

> So sorry it's been so long! I suck. Anyway, this chapter isn't super long but it's something to get me back in the groove of things.

Cas hadn’t been kidding about the feathers. They had dissolved - kinda like cotton candy - leaving behind tingles of pleasure that had rushed through his body in warm shivers. Dean had just laid out on the bed and let it happen, napping on and off, with Cas lying beside him. Dean couldn’t remember ever being this relaxed. Can, however, seemed particularly on edge.

“You ok?” Dean asked.

Cas smiled - a forced little stretch of his lips. “I’m good, Dean.”

“Liar.”

“Dean.”

Dean sat up. “You can tell me, ya know. Whatever it is.”

Cas rubbed the back of his neck. “Have you, um, noticed anything?”

“Buddy, you’re gonna have to be more specific?”

“With your body? Have you noticed any-“

“I feel damn good if that’s what you're asking.”

Cas swallowed and angled himself a bit more toward Dean, as if he really wanted Dean to pay attention. “I think you’re changing.”

Dean felt some of the blood drain away from his face. He’d been so caught up in how good Cas made him felt, in how much he wanted whatever was happening between them, that he hadn’t given much thought to it. But something did seem _off._

“You think it’s like _happening_?” Dean didn’t know how else to phrase it. He didn’t really like how that sounded though. Made him feel like they were in a M. Night Shyamalan movie. 

“We’re becoming more _compatible,_ I guess you might say.”

“And that means.”

Cas stood up from the bed. “It means we need to be very careful.”

“Because you could get me…pregnant?” That sounded really freaking creepy when he said it aloud.

“In my own way, yes, we discussed this, Dean.” There was an edge to Cas’s voice that pissed Dean off.

“We haven’t really discussed.”

“That’s not my fault.”

Dean stood up as well, coming over to Cas’s side of the bed and looking him dead on. “And it’s mine? I’m the one out of the loop here. I’m the one who has no idea what the fuck is going on. So, come on, man, enlighten me.”

Cas sighed and looked down at the floor. “When a grace and soul meet, especially when they’re bonded as ours are. It’s possible for a part of each to essentially break off and fuse together and form in the body of the soul-bearer something entirely else.”

“You mean nephilim?”

Cas nodded.

“And nephilim are so bad?”

Cas frowned. “They’re against nature. God never meant for their existence. He never planned for it.”

“So they’re monsters?”

Cas shrugged. “They’re powerful, extremely powerful, like angels. Yet ruled by emotions, by passions, as humans are. They’re not unlike the pagan gods. Some say, pagan gods, are the nephilim that managed to escape the great culling.”

“The great culling?”

“Yes, Dean. Not long after the evolution of humans, angels and humans began interacting, as often commanded by god or later by Michael. It hadn’t been foreseen that humans and angels would bond in this way, but when they did, we were left with powerful and uncontrollable nephilim with little loyalty to heaven. It was decided that they would be destroyed, and relationships with humans deeply discouraged - to the point where they were functionally banned.”

Dean let out a huff of air. “So what you’re telling me is that heaven has a big problem with us?”

“Well…yes, Dean.”

“Fuck heaven.”

“Dean.”

“No, I’m serious, Cas. Heaven can go royally screw itself because I’ve had enough. This isn’t the dark ages anymore. Heaven doesn’t make the rules anymore.”

“Then who does?”

Dean shook his head. “We do, Cas. We make them for ourselves.” Dean surged forward and kissed Cas hard on the mouth. It took Cas a moment before he responded, pulling Dean in even tighter.

“Everything you’ve said. It isn’t enough reason for us not to be together.”

“Having a nephilim and protecting it - that would start a war with heaven. They’d want to…they’d want to kill our…our child.” It seemed hard for Cas to say ‘child’. Dean understood that. It was hard to hear. It was a big thing.

“Look, Cas. I’m not saying we don’t be careful. I’m just saying that I’m not gonna let those winged dicks dictate how we love each other.”

Dean ran his hand down Cas’s chest, rested it on his hip. 

“Okay, Dean,” Cas said.

Dean smiled. This was what he wanted, right? For Cas to be on his side about all this, to be _with_ him, and damn those would tried to stop him? But then why now was he suddenly struck cold with fear?

 


End file.
